Wax sweating and crystallizing apparatus



Jan. 14, 1930. H. L. ALLAN ET AL 1,743,746

WAX SWEATING AND CRYSTALLIZING APPARATUS Filed Feb. 9. 1928 2 SheetsSheet 1 Arron Ens Jan. 14, 1930. H. L. ALLAN ET AL.

WAX SWEATING AND CRYSTALLIZING APPARATUS 4770/P/VE76 Patented Jan. 14,1930 UNITED STATES PATENT OFFICE HUGH LOGIE ALLAN AND JAMES-MOORE, orBIJRMAHQ,VIBRITISH INDIA, ASSIGNORS TO THE BURMAH OIL COMPANY LIMITED,or GLASGOW, SCOTLAND, A BRITISH c0320- RATION w x SWEATING AnnoRxsrALLIzme APPARATUS Application filed February 9, 1928, Serial No.253,158, and in Great BritainlMaroh 26, 1927.

This invention relates to apparatus for the heat-treatment of wax,comprising a closed vessel which is filled with wax or wax mixture tothe exclusion of air, means being 5 provided for uniformly heating andcooling the wax throughout the vessel.

Such apparatus is disclosed in the speci-.

fication of British Letters Patents Nos. 208195 and 243447 and UnitedStates Patents Nos. 1504923 and 1654232, and comprises a vessel which isdivided into superposed wax compartments by means of substantiallyhorizontal cells through which heating and cool- 26 wax compartment, ofaseries of transverse spiral pipe coils of relativelyclosepitch.

Each transverse partition preferably consists of a single thickness ofplate below a layer of reticulated or expanded metal and/or wire '25gauze which supports the superincumbent mass of wax.

Provision may be made for compensating for the contraction of the waxmass during the cooling phase, by the admission to the top of each waxcompartment of an additional charge of wax mixtures The admission ofsuch additional charge of; wax mix ture is herelnafter briefly termedsupercharglng.

plates do not in themselves provide suflicient heating effect to keepthe mass in the space between each transverse plate and its super posedWax support in a liquid state until the 40 heat of thewaxmixtureadmitted by'sup'ercharging the wax compartments during the cooling phaseis sufficient to keep the mass in 1 a liquid state in the aforesaidspace'beneath each wax support.

Final melting-out of the sweated or finished wax is effected by means ofsteam jets or open steam pipes situated in the space between thetransverse plate and superposed wax support, preferably at the-peripheryof According to the present invention, the- The aforesald transversepartitions or sweating operation is commenced, but the the top thereof;a

By resorting to the aforesaidsupercharging, the wax support can beplaced relatively close to the transverse plate, but when superchargingis not resorted to or when it is found necessary'or desirable, the waxsupport may be spaced sufiiciently' from the transverse plate toaccommodate a pipe coil in the intermediate space, hot water, hot oil orother heating medium being circulated through this pipe coil to effectpreliminary melting-out of the space between the transverse'plate andsuperposed wax support preparatory to sweating. Final melting-out of thesweated or finished wax may be eflected in this case by the provision ofheating pipes provided in the space beneath each wax support. v g r Theinventionwill now be hereinafter more particularly described withreference to the accompanying drawings whereon:

Fig. 1 is a vertical sectional elevation through an apparatusconstructed according to the present invention. In this view only oneset of pipe coils is illustrated in full lines, the other sets of pipecoils being denoted by broken lines.

Fig; 2 is a plan View of the apparatus with the cover plate removed. v

. Fig. 3 is a detail'of the vertical sectional elevationfshowing onecorner of one of the wax compartments. 7

Fig. 4 is a cross-sectional view through the jet- 36 of Fig, 3,showing-also the jet in end, v1ew.' j

Fig. 5 is a detail view. of the vertical sectional elevationof" asection of the central p p .I V

Fig 6 is a view similar to Fig. 3 showing one corner offajwa'xcompartment as constructed when supercharg'ing' is not practised andFig. '7 is a sectional view taken through the space 13 partially'show'nin Fig.6. I

Referring to the "drawings, the numeral 6 designates the outer shell'ofa preferably cylindrical vessel which is preferably suitably lagged, forexample, with cork and ce-' ment, and which is divided, into superposedthe said space, andif desired also by passit mg steam into eachcompartment at or near slightly dished or conical to form. trays,

wax compartments 7 by means of transverse plates, diaphragms orpartitions 8, which consist of a single thickness of plate having acentral aperture 9 (Fig. 5). In each compartment 7 is a series oftransverse spiral pipe coils 10, preterably of uniform pitch, throughwhich water, oil, brine or other suitable heating or cooling fluid iscirculated The transverse plates. 8 are preferably a short distanceabove which perforated or wire'gauze wax supports 11 are suppOl fid upona similarly di'shed' or conical layer of p e e herre to eted m ta 12-When the apparatus is designed for enbl ng the ax p rtmea st b Suprcharged, as in Fig 1;; to, 5 the expanded metal 12 may be supportedupon small discs- 1ar mhly of meta I pereha s nsnot practised, pipecoils 14s are fitted, in the space 13 (see Figs.

It will be seen that the partitions. & form trays toreceive the waxmixtare'that, the outershell 6: forms the, sides or the wax trays or thecompartments v The upper coils of each set oi spiral coils 10 may befurther apart than the lower-coilsof each set, but in an apparatusconstruct d to b p rch ged, the coilsshould preferably be evenly spaced,throughout the compartment. In order to melt the wax out of the space-13 below each waxsup:v

port, steam jet pipes .35 are arranged at the periphery of the saidspace and are: supplied 35, with steam from a steam header 37.

' structional economy. 7

The melting-out'of the wax from the compartments may also. be achievedby Pa sing w. steam into the u per part of each comps-rt ment, forexample, by theprovision near the top of each compartment of steam jetsor" pipes 44 connected to the steam header 37?. A central steam pipe 40extends through each header 3'? for freeing the headers 0t solidifiedwax, which is run off through drain pipe 41.;

The construction above described" enables the depth of the waxcompartments, to be considerably increased, viz, irom about 6 inches inthe construction shown in patent specification 1654232 to approximately30 ashe thereby ecting: an importa t con- The arrangement of the heatingelements in the form of pipe coils spaced closely thpoughout the mass atwas ndentreetment I leads to improved heat transference, by re:v

ducing the lag 01?. time inthe heat transfer. n f m r designs owaxsweating apparatus, as shown, eggin; Patent No. 16542325 the h at hadt travel along fins or. other heat conductors to the wax, whereas thehilt pipe o of th present invention are in close antas-t with t e was.hisgreate tempera re central ena les elese cuts te-b. ob?

ained in he swea ieg operation,v that; is to I srt-eaahles the: lesseesthe mala ia po s g pa -i F urthermore, the superch-arging of theapparatus is believed to be novel and enables the apparatus. to startsweating with a full charge, whereas in other existing apparatus forthis purpose, the charge is minus/the amount of contraction duringcooling. The still further advantage of supercharging is 7 that; the-topof a wax cake is at a higher temperature than the rest of the cake andso p ev nt any film; or skin of wax forming on the sur a e. whi h w ldpr v n d ops; fr the; underside of the-[transverse plates 8, or oilgathered in; depressions, from passing freely through themassduring-sweating.

oreover, in this apparatus, the wax on the gauzeor reticulated supportisnot; chilled or ChOked, a-sis often the case when water is used tosupport the wax, and in this apparatus, whether; O not a coil 14, beused below the reticulated support, as hereinafter described withreference to; Figs. 6. and 7 the a i theqspace 13fis not subjec ed to 01+ ing, as the coil 14; is only used for heating urposes, and; where noQoil 14 is fitted, the super-charging of the wax compartment belowprevents undue cooling of the wax in the space 1.3;

()ne of the; improvements charging; is that no heating or cooling agencyis; nece sary nde nea h t e reticulated wax supports,

We are of course aware that the use of coolingand heating coils inrelatively deep ent ng: undue sagg g, of the W h p metmg ireedrainage ofthe sweated 1 f the Wax.

The GOils 1Q maybe of'any convenient di-vi ameter of pipe, but theradial pitch of the ils shou dipreiierah y be 2 inches or not,

mor an ,4: inches nd. the ver i a i a tw en the Pipe co s hou d prferably be finches or no more than ches ug out up to the depth ofsolidified charge, that,

1 a up rcharged appar t The s ag ering Q the soils 1 so brings chalternate eo l les to the she l This arses. ement mpensa sfo t e healost y adiation rqrn theshell dead prev nts the sweating process frombeing delayed in the proximity of the shell 6. The staggering of thecoils 10 also provides additional support for the mass and improves thedistribution of heat throughout the mass.

According to the present construction, the wax feed and discharge pipeis centrally arranged and consists of a pipe 16 continuous throughoutthe apparatus and provided below each wax support with slots 38, thetransverse plate 8 being preferably flared downwards at the centre, ordished below the depth of the slot 38 and there welded to the centralpipe 16. Throughout the central pipe 16 is an inner steam pipe 21 formelting out the portion of the solidified charge in the pipe 16 beforethe sweating operation is commenced.

A branch connection 39 is provided at the upper end of the central pipe16 for charging the wax compartments and a discharge pipe 23 is providedat the lower end of the pipe 16, into which all the wax compartmentsdischarge through the slots 38 during the sweating operation. Thedischarge pipe 23 has a valved branch l2 which discharges the sweat ingsand finished wax into a distributing box -13, which distributes thematerial to the various receivers for the sweatings and diiferent gradesof wax.

At one side of the shell 6 is provided a vertical pipe or header "17having branch pipes 18 which open int-o the wax compartments 7 near thetop thereof. Theheader 17 serves for the escape of air from the wax icompartments during the filling thereof with wax mixture,and also servesfor super charging, 1. e. the admission of 011 or wax mlxture to thecompartments 7 in order to compensate for the contraction of the mass'in the compartments 7 during the coolingphase.

The branch pipes 18 may open close upto the underside of each transversepartition 8 by the provision of knee pipes. As soon as sweating iscommenced, the wax contained in the header 17 and feed pipe 16 is meltedout by passing steam through steam pipes 20 and 21 which extendcentrally through the ..header and feed pipes respectively.

In the construction shown, the vessel has a dished or conical bottom22.to prevent accumulation of sludge in the bottom of the vessel. a

A feature of the present apparatus is that it does not require to betilted towards one side, as is the case with the "apparatus disclosed inpatent specifications Nos. 150 1923 and 1654232.

The present invention also avoids the practice, commonly adopted where aperforated wax support is provided above the tray, of filling below theperforated wax support with water prior to charging the tray with waxmixture.

The method of operation of the apparatus is as follows The vessel isfirst brought to a temperature slightly above melting point of the waxmixture to be treated by circulating hot water, hot oil or other hotliquid through the pipe coils 10. Molten wax mixture is thenad water oroil circulated through the pipe coils 10. The cooling of the wax mixturecauses contraction of the mass in the vessel and the compartments arefilled automatically by admitting further liquid wax mixture tothecompartments 7 through the branch pipes 18 by closing the vent pipe24 to atmosphere and opening the header 17 through a valve or cock 26 toanoverhead tank, not'shown. The

compartments are thus fully charged to the" exclusion of air and coolingproceeds to the desired temperature. The sweating phase is commenced byfirst passing steam through the steam pipes 20 and 21 in order to clearthe 1 header 17 and-central pipe 16 of solidified wax. The melted wax inthe header 17 is run 05 through a drain pipe 27. The melted wax in thepipe 16 runs away through the'discharge'pipe 23 an'd'a distribution box,not shown,.t0 a receiver, not shown. The sweating process is thenaccomplished by circulating hot water, hot oil or other hot liquidthrough the pipe coils 10. The sweated wax is finally melted out of thecompartments 7 by admitting steam openly to the space 13 through thesteam jets 36. During the sweating process, the header 17 is opened toatmosphere through the vent pipe 24. The steam pipe 20 serves to heatany air drawn into the vessel through the header 17 during the sweatingphase.

The steam jets 36 may be supplied with either water or steam. This is anadvantage as it enables any sweatings below the wax support 11 whichhave not drained away properly during the sweating process to be washedaway.

Referring now more particularly to Fig. 2,

it will be seen that the ends of the pipe coils I 10 open intowaterspaces 28 and 29 formed in awater chest 30 which extends verticallyoutside the shell 6, the water spaces 28 and 29 being separated by avertical partition 31 and serving for the admission and outlet of waterfor circulation through the pipe coils 10,:

wheresupercharging is not adopted, the

. ompartmen he nhqle ma akes up the v rage tempe ure of t e we C s- I heppa tus illustr dt e P p coi s l ar l uppl ed f om the Water c est 0 sotha it is not P le o solate a y Particu r o l,

b P ion may b ma f r hi p pose if so e in o d r t isola e he upp Coilsas sweating proceeds.

' When the apparatus is constructed without P o s on t stipe h rging,ripe c s 1e e fi ted, a sh n in sin e Spa e 13 beneath each wax support.

T e p pe i s 1 a p v d d for heatin the space 13 between the partition 8and wax pp t 11 n r e t mel e ax out f this space before the sweatingoperation commences. Steam jet pipes 15 are also pro vided in the space13 to enable final meltingout of t e Swea cd r he Wax o be effected. I iI As will be seen from Fig. 7, the pipe coil 14 extends at its endthrough the water chest 30 and its inlet end is connected to a watersupply pipe 32. A steam pipe 33 connects with the water pipe 32 in orderthat steam may be admixed with the water circulated through the coil 14.The steam iet pipes 15 are for convenience a rang d. between the, loopsof the coil 14 and supplied with steam from a steam pipe 34.

Claims: 7

lQApparatus for the heat-treatment of wax comprising a closed uprightvessel, transverse dished or conical partitions extending across saidvessel and dividing said 'vessel into superposed wax compartments, a

series of superimposed transverse pipe coils in each compartment,aperforated wax support below each set of coils, a central pipe extendingvertically through the Vessel for charging'each compartment with waxmixture, and means for escape of theair dis placed during chargingpermitting complete charging to the exclusion of air. j r

2. Apparatus for the heat-treatment of wax as claimed in claim 1,wherein the pipe coilsa-re of spiral construction and uniform radialpitch throughout. I

3. Apparatus for the heat-treatment of wax as'claimed in claim 1,wherein the Supervertical intervals of preferably 2 inches but not morethan 4 inches.

5. Apparatus for the heat-treatment of wax as claimed in claim 1, havingauxiliary means for supplying wax mixture to fill the compartment-s. t

6. Apparatus for the heat-treatment of Wax as claimed in claim 1, havingsteam or water jets provided around the periphery of the spaceimmediately beneath each wax support.

7. Apparatus for the heat-treatment of wax as claimed in claim 1, inwhich a heating pipe and steam or water jet pipes are provided in aspace between each partition and wax support.

8. Apparatus for the heat-treatment of wax, Comprising an outer uprightcylindrical shell, dished partitions extending completely across theinterior of said shell to form trays the sides of which are formed bysaid shell, thereby to form enclosed wax compartments, a centralcharging and discharging pipe extending vertically through the vesseland having apertures opening into the lower part of each Waxcompartment, a series of pipe coils in each compartment, a perforatedwax support in the lower part of each compartment, a cover for saidvessel, and an air vent passage in said cover.

Apparatus for the heat-treatment of wax as claimed in claim 1,comprising a vertical pipe or header and branch pipes connecting'saidheader to the space at the top of each compartment for supplying waxmixture and for the supply of air to and its escape'from saidcompartments; 7

10. Apparatus for the heat-treatment of wax as claimed in claim 1,characterized in that the coils of each series are superimposed andstaggered in relation to one another to improve heat distribution andafford better support for the wax cake. 7

11 Apparatus for the heat-treatment of wax as claimedin claim 1,comprising a vertical header, connections from said header to.

the space at the top of each compartment, and a steam pipe in the headerfor heating wax mixture therein and for heating air entering thecompartments through the header. 12. Apparatus for the heat-treatment ofwax as claimed in claim 1, characterized in that the pipe coils openinto water spaces in a vertical chest at the side of the vessel.

In testimony whereof weaifix our signatures. V

,HUGH LOGIE ALLAN.

JAMES'MOORE.

imposed pipe coils are evenly spaced ver-.- 7

tically within each wax compartment.

4. Apparatus for the heat-treatment of" wax as claimed in claim 1,wherein the coils have a radial pitch of preferably 2 inches but notlnore than 4 inches andare. spaced. at

CERTIFICATE OF CORRECTION.

Patent No. 1,743,746. Granted January 14, 1930, to

I-IIUGH LOGIE ALLAN ET AL.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as foilows: Page 4.line 44, claim 1, before the word "across" insert the word "completely";and that the said Letters Patent should be read with this correctiontherein that the same may conform to the record of the case in thePatent Giiice Signed and sealed this 4th day of February, A. D. 1930.

M. J. Moore,

(' Sje al) Acting Commissioner of Patents.

